Shrapnel has the rare distinction of appearing in two episodes of Midsomer Murders as two different characters, in Death in Chorus and Written in Blood. Shrapnel appeared in an episode of Jonathan Creek as Professor Lance Graumann in the episode The Omega Man. He appears in Chemical Wedding alongside Simon Callow, telling the tale of the resurrection of occultist Aleister Crowley.

Shrapnel is the son-in-law of British film actress Deborah Kerr, through his 1975 marriage to her younger daughter Francesca Ann Bartley. They have three sons, the actors Lex Shrapnel (b. 1979) and Tom Shrapnel (b. 1981), and the writer Joe Shrapnel (b. 1976). They live in Highbury, North London.